Hosts are not responsible for traveler’s visas. Each country has a specific legislation regarding to visas, so it’s the traveler’s responsibility to research about the right type of visa for their experience.
Remember that Worldpackers is a platform that connects hosts and travelers solely to promote collaborative experiences. The travelers are solely responsible for any and all other requirements relating to travel logistics, including but not limited to: tickets, passports, local transport, travel insurance, and visas, for example.
You can click here for more informations about travelers & visa.